The UK Hackspace Foundation maintain an accurate list of active UK spaces:

http://hackspace.org.uk/view/Main_Page

It looks like the nearest ones to you are Manchester and Leeds, both of which are excellent. If they're too far away then you should start a new space!

This is the guide we give to people when they ask for advice on how to get going:

http://hackspace.org.uk/view/Starting_a_Hackerspace

As they note, the traffic from HN has meant that their main page isn't a full list. There's dozens when you look at the UK category http://hackerspaces.org/wiki/United_Kingdom

There is one in Bristol yet its a mess and barely bigger than a 1 car garage. Their page vastly exaggerates their facilities.